.nav{                   
    height: 60px;
     background: white;
     padding-top: 15px;  
     width: 1000px;
     height: 60px;
     margin-left: auto;
     margin-right: auto; 
     margin-bottom: -10px; 
     font-size: 18px;            
 }

 .menu a{
     float: left;
     text-decoration: none;
     color: #5d5d5d;
     text-align: center;
     display: block;
     width: auto;
     font-size: 17px;
     line-height: 40px;
 }